Many people that I have spoken with say they don’t know much about it, so I’ll start with a short description from Wikipedia.
“Coalbed methane is a form of natural gas extracted from coal beds. In recent decades it has become an important source of energy in the United States, Canada, and other countries. Australia has rich deposits where it is known as coal seam methane. Also called coalbed gas, the term refers to methane adsorbed into the solid matrix of the coal. It is called ‘sweet gas’ because of its lack of hydrogen sulfide. The presence of this gas is well known from its occurrence in underground coal mining, where it presents a serious safety risk.”
That sounds simple enough, but what happens when you try to get it to the surface? It would appear that CBM extraction is not as nasty as some other ways of using energy from coal beds. However, there are still some environmental considerations. There always are.
From Wikipedia again: “CBM wells are connected by a network of roads, pipelines, and compressor stations. These structures can compromise the scenic quality of the landscape, fragment wildlife habitat, and displace local wildlife populations. Over time, wells may be spaced more closely in order to extract the remaining methane. Additionally, the produced water may contain undesirable concentrations of dissolved substances. Water withdrawal may depress aquifers over a large area and affect groundwater flows.”
Ah yes, water. It seems that there is always something about water. CBM extraction is basicly accomplished by pumping water out of the coal seam, so it is clear that there is a potential for disturbing water supplies, at least indirectly. But what happens with the waste water?
This contaminated water is called “produced water” by the industry. Disposal of this wastewater can have disastrous consequences for agricultural land, drinking water supply, and fish and wildlife. The problems vary from area to area and with the engineering solutions chosen, but it is certainly something which is worth keeping an eye on.
In B.C., the disposal of produced water is governed by the Produced Water Code of Practice, which is enforced by the Oil and Gas Commission. I have no idea how good this commision is at looking out for the average citizen. I can only hope that they have our best interests at heart.
A CBM well typically produces 0.01 percent the amount of gas that a conventional well does. Is it even worth it? To get enough gas they have to put in more wells closer together. Wells slowly run down and more get added. No matter what happens, some people’s toes are going to be stepped on.
Land owners close to CBM developments need to consider some special issues. For example, if a company wants to drill for coalbed methane on your private land, there is nothing you can do to stop them. CBM development can cause private land values to drop. A study in La Plata Colorado showed a 20 percent drop in value for property with wells. An Alberta study showed a 10 percent drop in property values around a CBM development. Will our government, who supports development of a coalbed gas industry, compensate land owners? Your guess is probably the same as mine.
There is a long list of possible dangers. Some are tragic but, to be fair, many are not realities in most areas. An interesting one is the possibility of starting underground coal fires because of the dewatering and thus exposing more coal to oxygen. This situation can also cause existing fires to spread. Under some conditions, fires can introduce even more contaminants into drinking water than would have happened otherwise.
One thing is a reality in all areas: you can’t make promises based on the behavior of nature. It simply isn’t possible to accurately predict how much lower your well water will be, or whether there will be any surprises in the geology. Underground fires may be uncommon and unlikely to occur, but what about above ground fires? This has happened in at least one case. The initial setup of a CBM well involves a lot of burnoff but regardless of any human activity it is still a safe bet that a forest fire will occur at some point. I wonder how a CBM installation will fare under those conditions. I bet it could be spectacular!
The Ministry of Energy, Mines and Petroleum Resources promises to “balance environmental protection, economic growth and community interests”. How are they going to be able to do this, and is it even possible to make those promises? In the end, the decisions will probably be made by people who don’t live here and who see that “balance” differently than we do. The gas produced is for export and the money made also goes out of the area. Let’s get real. You can’t balance our loss with someone elses gain.
Some people beleive that CBM is a good temporary solution to the world’s increasing energy demands because it appears to be less intrusive than some other methods. However, the issues are obviously not so simple. There have been some unpleasant experiences with CBM in the US and the potential exists for the same problems here. We’ll see how it develops, but my guess is that local concerns will be ignored in order to get the industry going. Let’s hope that I’m wrong. -OJ
1- The Ministry of Energy, Mines and Petroleum Resources has a web site dedicated to coalbed gas.
2- For those who wish to become more involved in the issues, there are some organizations who are working toward the responsible use of CBM. In BC there is Citizens Concerned About Coalbed Methane who have been working out of Fernie, BC, since 1998.
3- The US based Energy Justice is another advocacy group which also acts as a clearinghouse, providing information to the general public and the media. They have a good page on CBM technology.